This invention relates to a surgical needle comprising a point and dual cutting blades. The point is defined by a symmetrical angle of width and an angle of slope. The needle point geometry and the dual cutting blades provide a flap incision and a reduction in the tissue penetration properties.
The Applicants are not aware of any prior art which, in their respective judgements as persons skilled in the art of surgical needle of this invention. However, to fully develop the background of the invention and establish the state of the art, the following references are cited:
U.S. Pat. No. 3,094,123 issued June 18, 1963 which discloses a surgical needle having an angle of slope and an angle of sharpness and providing a reduction in tissue penetration force; and
U.S. Pat. No. 2,841,150 issued July 1, 1958 which discloses a surgical needle having a triangular cross-section. Both of these patents are incorporated by reference.
The surgical needle of this invention has advantages over the references above. The needle point geometry and the V-shape cross-section provide a reduction in the tissue penetration force and a flap incision, rather than a circular, eliptical or triangular incision of the prior art needles. The advantage of the flap incision is that the flap formed can then close over the puncture defect. This may accelerate the physiological healing of the puncture defect. The flap may also reduce fluid leakage from soft tissue. Another advantage is the dual cutting blades which can provide up to four cutting edges.
Still another advantage is that the V-shape cross-section of the needle is based on a structural beam concept (which is described in U.S. Pat. No. 2,841,150). The thickness of the needle sides can thus be reduced while providing sufficient rigidity to penetrate tissue. Alternatively, the needle height and width can be decreased which reduces the tissue penetration force.
The needle of this invention is useful as a cutting edge or a taper point surgical needle. The needle is used in the same manner as a conventional cutting edge or taper point needle.
A surgical needle providing a reduction in the tissue penetration force and a flap incision has now been invented. A straight or curved needle is within the scope of the invention. The needle comprises a penetration portion, a middle portion and a butt portion. The penetration portion initiates at a point. The point is defined by a symmetrical angle of width and an angle of slope. The penetration portion terminates in dual cutting blades having a V-shape cross-section. The cutting blades are joined at the apex of the V-shape. The butt portion of the needle has strand attachment means.
In a preferred embodiment, the point is defined by a symmetrical angle of width of about 20.degree. to 35.degree.. In another preferred embodiment, the point is defined by an angle of slope of about 20.degree. to 35.degree.. In other preferred embodiments, the sides of the V-shape cross-section have an included angle of about 60.degree.; and, the middle portion has a cross-section as described in FIG. 7 below or a V-shape cross-section.